Previously, it only ever fired for zeros which formed null pointers.
Now, hilariously, in C++98 this was almost anything. Including tricks
like warning on the divisor in this code:
typedef char c3[3];
size_t f(c3* ptr) {
return (sizeof(ptr) / sizeof(*ptr)) / (size_t)(!(sizeof(ptr) % sizeof(*ptr)));
}
Why the RHS of the outer divide is a null pointer constant is a sordid
tale of sorrow. Anyways, the committee fixed this for C++11 and onward
as part of core isssue 903, and Richard recently implemented this fix
causing the warning to go away here (and elsewhere).
This patch restores the warning here and adds it for numerous other
somewhat obvious gaffes:
int g(int x) {
return x / (int)(0.0);
}
The patch is essentially just using the full power of our constant
folding in Clang to produce the warning, but insisting that it must fold
to an *integer* which is zero so that we don't get false positives
anywhere.
llvm-svn: 183970
This warning triggers on the logical not of a non-boolean expression on the
left hand side of comparison. Often, the user meant to negate the comparison,
not just the left hand side of the comparison. Two notes are also emitted,
the first with a fix-it to add parentheses around the comparison, and the other
to put parenthesis around the not expression to silence the warning.
bool not_equal(int x, int y) {
return !x == y; // warn here
}
return !(x == y); // first fix-it, to negate comparison.
return (!x) == y; // second fix-it, to silence warning.
llvm-svn: 183688
is evaluated in a condition expression and then
dereferenced to envoke the block. This is
pr15663 and I applied a slight variation of the
patch with a test case. (patch is from
Arthur O'Dwyer). Also // rdar://14085217
llvm-svn: 183471
handle temporaries which have been lifetime-extended to static storage duration
within constant expressions. This correctly handles nested lifetime extension
(through reference members of aggregates in aggregate initializers) but
non-constant-expression emission hasn't yet been updated to do the same.
llvm-svn: 183283
common function. The C++1y contextual implicit conversion rules themselves are
not yet implemented, however.
This also fixes a subtle bug where template instantiation context notes were
dropped for diagnostics coming from conversions for integral constant
expressions -- we were implicitly slicing a SemaDiagnosticBuilder into a
DiagnosticBuilder when producing these diagnostics, and losing their context
notes in the process.
llvm-svn: 182406
is used for Objective-C++’s dictionary subscripting. This is done by filtering
out all placeholder types before check on lowering of the
common expression is done. // rdar://1374918.
Reviewed by John McCall.
llvm-svn: 182120
a FieldDecl from it, and propagate both into the closure type and the
LambdaExpr.
You can't do much useful with them yet -- you can't use them within the body
of the lambda, because we don't have a representation for "the this of the
lambda, not the this of the enclosing context". We also don't have support or a
representation for a nested capture of an init-capture yet, which was intended
to work despite not being allowed by the current standard wording.
llvm-svn: 181985
The most common (non-buggy) case are where such objects are used as
return expressions in bool-returning functions or as boolean function
arguments. In those cases I've used (& added if necessary) a named
function to provide the equivalent (or sometimes negative, depending on
convenient wording) test.
DiagnosticBuilder kept its implicit conversion operator owing to the
prevalent use of it in return statements.
One bug was found in ExprConstant.cpp involving a comparison of two
PointerUnions (PointerUnion did not previously have an operator==, so
instead both operands were converted to bool & then compared). A test
is included in test/SemaCXX/constant-expression-cxx1y.cpp for the fix
(adding operator== to PointerUnion in LLVM).
llvm-svn: 181869
This patch renames getLinkage to getLinkageInternal. Only code that
needs to handle UniqueExternalLinkage specially should call this.
Linkage, as defined in the c++ standard, is provided by
getFormalLinkage. It maps UniqueExternalLinkage to ExternalLinkage.
Most places in the compiler actually want isExternallyVisible, which
handles UniqueExternalLinkage as internal.
llvm-svn: 181677
MSVC provides __wchar_t. This is the same as the built-in wchar_t type
from C++, but it is also available with -fno-wchar and in C.
The commit changes ASTContext to have two different types for this:
- WCharTy is the built-in type used for wchar_t in C++ and __wchar_t.
- WideCharTy is the type of a wide character literal. In C++ this is
the same as WCharTy, and in C it is an integer type compatible with
the type in <stddef.h>.
This fixes PR15815.
llvm-svn: 181587
EmitCapturedStmt creates a captured struct containing all of the captured
variables, and then emits a call to the outlined function. This is similar in
principle to EmitBlockLiteral.
GenerateCapturedFunction actually produces the outlined function. It is based
on GenerateBlockFunction, but is much simpler. The function type is determined
by the parameters that are in the CapturedDecl.
Some changes have been added to this patch that were reviewed as part of the
serialization patch and moving the parameters to the captured decl.
Differential Revision: http://llvm-reviews.chandlerc.com/D640
llvm-svn: 181536
- References to ObjC bit-field ivars are bit-field lvalues;
fixes rdar://13794269, which got me started down this.
- Introduce Expr::refersToBitField, switch a couple users to
it where semantically important, and comment the difference
between this and the existing API.
- Discourage Expr::getBitField by making it a bit longer and
less general-sounding.
- Lock down on const_casts of bit-field gl-values until we
hear back from the committee as to whether they're allowed.
llvm-svn: 181252
Previously, this compound literal expression (a GNU extension in C++):
(AggregateWithDtor){1, 2}
resulted in this AST:
`-CXXBindTemporaryExpr [...] 'struct Point' (CXXTemporary [...])
`-CompoundLiteralExpr [...] 'struct AggregateWithDtor'
`-CXXBindTemporaryExpr [...] 'struct AggregateWithDtor' (CXXTemporary [...])
`-InitListExpr [...] 'struct AggregateWithDtor'
|-IntegerLiteral [...] 'int' 1
`-IntegerLiteral [...] 'int' 2
Note the two CXXBindTemporaryExprs. The InitListExpr is really part of the
CompoundLiteralExpr, not an object in its own right. By introducing a new
entity initialization kind in Sema specifically for compound literals, we
avoid the treatment of the inner InitListExpr as a temporary.
`-CXXBindTemporaryExpr [...] 'struct Point' (CXXTemporary [...])
`-CompoundLiteralExpr [...] 'struct AggregateWithDtor'
`-InitListExpr [...] 'struct AggregateWithDtor'
|-IntegerLiteral [...] 'int' 1
`-IntegerLiteral [...] 'int' 2
llvm-svn: 181212
the actual parser and support arbitrary id-expressions.
We're actually basically set up to do arbitrary expressions here
if we wanted to.
Assembly operands permit things like A::x to be written regardless
of language mode, which forces us to embellish the evaluation
context logic somewhat. The logic here under template instantiation
is incorrect; we need to preserve the fact that an expression was
unevaluated. Of course, template instantiation in general is fishy
here because we have no way of delaying semantic analysis in the
MC parser. It's all just fishy.
I've also fixed the serialization of MS asm statements.
This commit depends on an LLVM commit.
llvm-svn: 180976
temporary to an lvalue before taking its address. This removes a weird special
case from the AST representation, and allows the constant expression evaluator
to deal with it without (broken) hacks.
llvm-svn: 180866
a dependent-scope id expression when a templated member function of a
non-templated class references an unknown identifier, since instantiation won't
rebuild it (and we can tell at parse time that it'll never work). Based on a
patch by Faisal Vali!
llvm-svn: 180701
will fire on code such as:
cout << x == 0;
which the compiler will intrepret as
(cout << x) == 0;
This warning comes with two fixits attached to notes, one for parentheses to
silence the warning, and another to evaluate the comparison first.
llvm-svn: 179662
Add CapturedDecl to be the DeclContext for CapturedStmt, and perform semantic
analysis. Currently captures all variables by reference.
TODO: templates
Author: Ben Langmuir <ben.langmuir@intel.com>
Differential Revision: http://llvm-reviews.chandlerc.com/D433
llvm-svn: 179618
http://lab.llvm.org:8011/builders/clang-x86_64-darwin10-gdb went back green
before it processed the reverted 178663, so it could not have been the culprit.
Revert "Revert 178663."
This reverts commit 4f8a3eb2ce5d4ba422483439e20c8cbb4d953a41.
llvm-svn: 178682
For variables and functions clang used to store two storage classes. The one
"as written" in the code and a patched one, which, for example, propagates
static to the following decls.
This apparently is from the days clang lacked linkage computation. It is now
redundant and this patch removes it.
llvm-svn: 178663
variable in a C99 inline (but not static-inline or extern-inline)
function definition.
The standard doesn't actually say that this doesn't apply to
"extern inline" definitions, but that seems like a useful extension,
and it at least doesn't have the obvious flaw that a static
mutable variable in an externally-available definition does.
rdar://13535367
llvm-svn: 178520
'isa' ivar is accessed provided it is the first
ivar. Fixit hint will follow in another patch.
This is continuation of // rdar://13503456
llvm-svn: 178313
Eli Friedman